Maʿānī al-ʾAkhbār > The meaning of haqila, muzabana, ‘araya, mukhabarat, mukhadhara, munabadha, mulamasa, the selling of pebble and other things that were declared forbidden
Hadith #28

وقال صلى الله عليه وآله: لا تناجشوا ولا تدابروا. معناه أن يزيد الرجل الرجل في ثمن السلعة وهو لا يريد شراءها ولكن ليسمعه غيره فيزيد لزيادته، والناجش الخائن. وأما التدابر فالمصارمة والهجران مأخوذ من أن يولي الرجل صاحبه دبره ويعرض عنه بوجهه.

He, Allah’s blessings be upon him and his Family, also said: «Do not perform tanajush nor tadabur.» Its meaning is that a man increases to another man the price of a merchandise while he does not want to buy it, but in order for another to hear him and bid due to his bidding. One who performs tanajush is a traitor. As for tadabur, it is quarreling and severance of relation. It stems from that a man turns his backside to his companion and turns his face from him.